Display element, display and method for manufacturing display

ABSTRACT

A display element containing: (a) a first electrode which is transparent and is controlled by a driver element; (b) a second electrode; and (c) a solid polymer electrolyte layer containing a colorant and metal ions, the solid polymer electrolyte layer being provided between the first electrode and the second electrode, wherein the first electrode has an anti-reflecting layer on a side opposite to the solid polymer electrolyte layer.

TECHNICAL FIELD

The present invention relates to a display element, a display apparatusand a manufacturing method thereof, utilizing a material, which changescolor by an electrochemical redox reaction, as a display material.

BACKGROUND

Heretofore, it has been practiced to print the articles, which aredelivered as an electronic document, as a hard copy for reading,however, in recent years, a display element, which enables readingwithout printing a hard copy, has been desired because an increasingvolume of articles are delivered due to popularization of intranet andinternet or increase of transmission speed.

As these display elements for reading, there is a CRT, a liquid crystaldisplay or an organic EL display. However, these displays causesignificant fatigue because of humane technological reasons due to beingemission types and are pointed out not to withstand reading for a longtime. Further, there is a disadvantage that a reading place is limitedto places where a computer can be installed.

To overcome these disadvantages, recently proposed are a reflection typedisplay which is so-called a paper like display or an electronic paper,and primarily includes such as a method to transfer colored particlesbetween electrodes by electrophoresis (for example, refer to patentliterature 1), a method to rotate a particles provided with dichroism bya magnetic field (for example, refer to patent literature 2), or anelectrochromic display element which utilizes a redox reaction of ametal ion (for example, refer to patent literatures 3 and 4).

Among these, in an electrochromic display element, which utilizes aredox reaction of a metal ion, there are proposed one provided with awhite reflective plate on the back surface (for example, refer to patentliterature 5) and one in which a colorant is incorporated into polymersolid electrolyte to increase the whiteness (for example, refer topatent literature 6). However, they cannot be said sufficient aswhiteness against human vision.

[Patent Literature 1] U.S. Pat. No. 6,120,588

[Patent Literature 2] U.S. Pat. No. 5,754,332

[Patent Literature 3] JP-A No. 10-133236 (Hereinafter, JP-A refers toJapanese Patent Publication Open to Public Inspection)

[Patent Literature 4] JP-A No. 10-148851

[Patent Literature 5] JP-A No. 11-101994

[Patent Literature 6] JP-A No. 2002-258327

The present invention has been made in view of the above problems, andan objective of this invention is to provide a display element, adisplay apparatus and a manufacturing method thereof, employing adisplay material in which the whiteness of the background issufficiently increased as visional characteristics and which performscolor change by an electrochemical redox reaction.

SUMMARY OF THE INVENTION

The above object of this invention has been achieved by the followingconstitutions.

-   (1)

A display element comprising:

-   -   (a) a first electrode which is transparent and is controlled by        a driver element;    -   (b) a second electrode; and    -   (c) a solid polymer electrolyte layer containing a colorant and        metal ions, the solid polymer electrolyte layer being provided        between the first electrode and the second electrode,

wherein the first electrode has an anti-reflecting layer on a sideopposite to the solid polymer electrolyte layer.

-   (2)

The display element of the above-described item 1,

wherein the first electrode is provided on a transparent substrate.

-   (3)

The display element of the above-described item 2,

wherein the anti-reflecting layer has a smaller reflection index thanthe transparent substrate.

-   (4)

The display element of the above-described item 3,

wherein the anti-reflecting layer contains a fluorinated compound as amain component.

-   (5)

The display element of the above-described item 4,

wherein the metal ions are selected from the group consisting of ions ofbismuth, copper, silver, lithium, iron, chromium, nickel, cadmium andmixtures thereof.

-   (6)

The display element of the above-described item 5,

wherein the colorant is an inorganic pigment, an organic pigment or adye.

-   (7)

The display element of the above-described item 6,

wherein the inorganic pigment is selected from the group consisting of apowder of titanium oxide, calcium carbonate, magnesium oxide andaluminum oxide.

-   (8)

The display element of the above-described item 1,

wherein the colorant is selected from the group consisting of a powderof titanium oxide, calcium carbonate, magnesium oxide and aluminumoxide, and a surface of the powder is treated with ahydrophobicity-giving agent.

-   (9)

The display element of the above-described item 8,

wherein an average diameter of the colorant is from 0.1 to 1.0 μm.

-   (10)

The display element of the above-described item 8,

wherein the hydrophobicity-giving agent is a metal alkoxide, anorganometallic compound containing a metal-to-halogen bond in themolecule or an organometallic compound containing a metal-to-metal bondin the molecule.

-   (11)

The display element of the above-described item 1,

wherein the first electrode which is transparent comprises SnO₂, In₂O₃or mixtures thereof.

-   (12)

The display element of the above-described item 1,

wherein the second electrode is a metallic thin film.

-   (13)

The display element of the above-described item 1,

wherein the solid polymer electrolyte is selected from the groupconsisting of polyethyleneoxide, polypropyleneoxide, polyethyleneimine,polyethyelenesulfide (each skeleton of which is represented by—(C—C—O)_(n)—, —(C—C(CH₃)—O)_(n)—, —(C—C—N)_(n)— or —(C—C—S)_(n)—,respectively); polymethylmethacrylate, polyfluorovinylidene,polychlorovinylidene, polycarbonate, polyacryonitrile, the solid polymerelectrolyte may be a mixtures of the aforesaid polymers or a pluralityof layers of the aforesaid polymers; provided that the solid polymerelectrolyte further contains a metal salt or an alkylammonium salt.

-   (14) A display apparatus comprising a plurality of display elements    which forms a display panel, each display element comprising:    -   (a) a first electrode which is transparent and is controlled by        a driver element;    -   (b) a second electrode; and    -   (c) a solid polymer electrolyte layer containing a colorant and        metal ions, and being provided between the first electrode and        the second electrode,

wherein the first electrode has an anti-reflecting layer on a sideopposite to the solid polymer electrolyte layer.

-   (15) A method of producing a display apparatus comprising the steps    in the order named:    -   (a) forming an anti-reflecting layer on a transparent substrate;    -   (b) forming a transparent electrode and a driver element on the        transparent substrate on a side opposite to the anti-reflecting        layer;    -   (c) forming a solid polymer electrolyte layer containing a        colorant and metal ions on the transparent substrate; and    -   (d) forming a common electrode at an opposed position to the        transparent electrode.-   (16) A method of producing a display apparatus comprising the steps    in the order named:    -   (a) forming a transparent electrode and a driver element on a        transparent substrate;    -   (b) forming a solid polymer electrolyte layer containing a        colorant and metal ions on the transparent substrate;    -   (c) forming a common electrode at an opposed position to the        transparent electrode; and    -   (d) forming an anti-reflecting layer on the transparent        substrate at a side opposite to the transparent electrode and        the driver element.-   (17)

A method of producing a display apparatus comprising the steps in theorder named:

-   -   (a) forming a transparent electrode and a driver element on a        transparent substrate;    -   (b) forming an anti-reflecting layer on the transparent        substrate at a side opposite to the transparent electrode and        the driver element;    -   (c) forming a solid polymer electrolyte layer containing a        colorant and metal ions on the transparent substrate on a side        which is formed the transparent electrode and the driver        element;    -   (d) forming a common electrode at an opposed position to the        transparent electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial oblique view drawing of a display apparatusaccording to this invention.

FIG. 2 is a cross-sectional drawing of a display apparatus according tothis invention.

FIGS. 3( a)-3(f) are process cross-sectional drawings showing amanufacturing method of a display apparatus according to this invention.

FIGS. 4( a)-4(f) are process cross-sectional drawings showing amanufacturing method of a display apparatus according to this invention.

FIGS. 5( a)-5(f) are process cross-sectional-drawings showing amanufacturing method of a display apparatus according to this invention.

FIG. 6 is a block diagram of a display apparatus according to thisinvention.

MOST PREFERRED EMBODIMENT OF THE INVENTION

In the following, this invention will be detailed.

In the following, embodiments of this invention will be detailedreferring to FIGS. 1-6. However, this invention is not limited thereto.

A display apparatus of this invention is characterized in that a polymersolid electrolyte layer containing a metal ion and a colorant and acommon electrode, which is common to each pixel as the second electrode,are accumulated in this order on a transparent pixel electrode as thefirst transparent electrode, which is controlled by a TFT (Thin FilmTransistor) as a drive element, and a plural number of display elementsprovided with an anti-reflecting layer on the surface opposite to thesurface, on which a polymer solid electrolyte layer has beenaccumulated, of a transparent pixel electrode as the first transparentelectrode controlled by a TFT as a drive element are arranged in a planeform.

FIG. 1 is a partial oblique view drawing of a display apparatus of thisinvention. A display apparatus of this invention is formed so as toconstitute one pixel by combining each one of transparent pixelelectrode 12 and TFT 13, and each pixel is arranged on transparentsupport 11 in a matrix form. A transparent support utilized hereincludes transparent glass substrates such as a quartz glass plate and awhite board glass plate, however, is not limited thereto and alsoincludes resin films of polyester type resin such as polyethylenenaphthalate and polyethylene terephthalate; cellulose ester type resinsuch as cellulose acetate; fluorine type resin such as polyfluorinatedvinylidene and fluoroinatedethylene-hexafluoropropylene copolymer,polyether type resin such as polyoxymethylene; polyolefins such aspolystyrene, polyethylene, polypropylene, polymethylpentene andnorbornene type ring-opening polymer; acryl type resin such aspolymethyl methacrylate; polyimides such as polyimide-amide andpolyetherimide, polyamide, polycarbonate, polyacetal, polyallylate,polyether ketone, polysulfone and polyether sulfone. In the case ofemploying these resin films as a support, it is possible to make a rigidsubstrate form which hardly bends, however, also possible to make a filmform constitution provided with flexibility, and further accumulatedsupports, in which a transparent glass substrate and a resin film, or aplural types of resin films are accumulated, can be appropriatelyutilized for the purpose of compatibility of flexibility and strength.

An anti-reflecting layer 18 is arranged on the opposite surface to thesurface, on which transparent pixel electrode 12 and TFT 13 areprovided, that is the so-called observing side, and this anti-reflectinglayer 18 is provided to more clearly observe a material described later,which changes color by an electrochemical redox reaction, and preferablyhas a refractive index not larger than that of transparent support 11.

As a material to form such an anti-reflecting layer is not specificallylimited provided the refractive index is not larger than that oftransparent support 11, however, for example, metal fluorides such asALF₃, MgF₂, ALF₃·MgF₂ and CaF₂; and organic fluorides like homopolymers,copolymers, graft polymers or block polymers, containing a fluorineatom, such as vinylidene fluoride and Teflon (R); and modified polymersmodified by a fluorine atom containing functional group; are preferablewith respect to the refractive index not larger than that of theaforesaid transparent support.

Herein, a method to provide a fluorine-containing compound on a supportis not indiscriminately determined depending on the types of a supportand a fluorine-containing compound, however, commonly known methods suchas a sol-gel method, a vacuum evaporation method, a spattering method, aDVD method and a coating method, or methods described in such as JP-ANos. 7-27902, 2001-123264 and 2001-264509, can be utilized byappropriate selection.

Transparent pixel electrode 12 is comprised of a transparent conductivefilm formed as a near rectangle or square pattern, each pixel beingisolated, and TFT 13 is arranged on the part of each pixel, as shown inFIG. 1. Herein, as the film of transparent pixel electrode 12 comprisinga mixture of SnO₂ or In₂O₃, that is a so-called ITO film, or a coatedfilm of SnO₂ or In₂O₃ can be utilized. These ITO film and a coated filmof SnO₂ or In₂O₃ may be doped with Sn or Sb, and such as MgO and ZnO maybe further incorporated. Further, as TFT 13, materials utilized incommonly known semiconductor manufacturing techniques employed for suchas a liquid crystal display can be utilized by appropriate selection,and also utilized may be an organic TFT comprising organic compoundsdescribed in such as JP-A Nos. 10-125924, 10-135481, 10-190001 and2000-307172.

TFT 13 formed for each pixel is selected by a wiring being not shown inthe drawing and controls the corresponding transparent pixel electrode12. TFT 13 is very effective to prevent cross talk between pixels. TFT13 is formed, for example, so as to occupy one corner of a transparentpixel electrode, however, it may be provided with a structure in whichtransparent pixel electrode 12 is piled on TFT 13 in the accumulationdirection. Specifically, a gate line and a data line are connected toTFT 13, a gate electrode of each TFT being connected to each gate line,a data line being connected with one end of the source and drain of eachTFT 13, and the other end of the source and drain each are electricallyconnected with transparent pixel electrode 12. Herein, a drive elementother than TFT 13 may be comprised of other materials provided they arematrix drive circuits utilized for a plane display element such as aliquid display and can be formed on a transparent substrate.

In a display apparatus of this invention, a metal ion is contained inpolymer solid electrolyte layer 14, and the metal ion changes color byan electrical redox reaction. That is, visualization is possible by areversible reaction of an electrochemical precipitation, which isso-called electrolytic plating, and elution as the reverse reaction ofsaid precipitation. Metal ions, which can perform coloration anddiscoloration by such electrochemical precipitation and elution, are notspecifically limited and include each ion of bismuth, copper, silver,lithium, iron, chromium, nickel and cadmium, or ions comprisingcombinations thereof. Preferable among them are a bismuth ion and asilver ion, because they can easily advance the reversible reaction.

Polymer solid electrolyte layer 14 is comprised of a matrix polymerbeing dissolved together with a support electrolyte, and saidelectrolyte includes lithium salts such as LiCl, LiBr, LiI, LiBF₄,LiClO₄, LiPF₆ and LiCF₃SO₃; potassium salts such as KCl, KI and KBr;sodium salts such as NaCl, NaI and NaBr; or tetraalkylammonium saltssuch as tetramethylammonium borofluoride, tetrabutylammoniumperchlorate, tetrabutylammonium borofluoride and tetrabutylammoniumhalide. The alkyl chain lengths of the quarternary ammonium saltsdescribed above may be same or different, and appropriately utilizedalone or in combination of at least two types.

In polymer solid electrolyte layer 14, a colorant is contained toimprove the contrast, and commonly known inorganic pigments, organicpigments or dyes, provided a sufficient contrast can be obtained againstthe coloration by a redox reaction of a metal ion, may be utilized byappropriate selection. Herein, in the case that coloration of a metalion is black as described above, preferably utilized is a white coloranthaving a high covering power as a background color, and such a colorantincludes, for example, titanium dioxide, calcium carbonate, silica,magnesium oxide and aluminum oxide.

The mixing ratio of this colorant in the case of utilizing inorganicparticles is preferably approximately 1-20 weight %, more preferablyapproximately 1-10 weight % and furthermore preferably 5-10 weight %.This is because inorganic white particles such as titanium oxide are notsoluble but only dispersed in a polymer, and inorganic particles maycoagulate when the mixing ratio increases resulting in uneven opticaldensity. Further, since inorganic particles have no ionic conductivity,increase of the mixing ratio induces decrease of conductivity of polymersolid electrolyte layer 14. The upper limit of the mixing ratio isapproximately 20 weight %, taking the both points into consideration.

Further, in polymer solid electrolyte layer 14, such as titanium oxide,calcium carbonate, magnesium oxide or aluminum oxide, the surface ofwhich has been subjected to a surface treatment by a hydrophobicityproviding agent, may be added as a colorant. This is preferable withrespect to dispersibility at the time of preparation of a polymer solidelectrolyte layer forming composition described later or preventingcoagulation of colorant each other after polymer solid electrolyte layerhas been formed, which results in maintaining the whiteness even whenthe apparatus is used for a long time.

A surface hydrophobicity providing agent to make the above-describedcolorant surface hydrophobic includes metal alkoxides, organometalliccompounds having a bond between a metal and at least one halogen atom,or organometallic compounds having a metal-metal bond, and surfacetreatment is performed preferably by at least one type selected fromthese compounds.

Such metal alkoxides, organometallic compounds having a bond between ametal and at least one halogen atom, or organometallic compounds havinga metal-metal bond include, for example, various alkoxides,organometallic compounds having a bond between a metal and at least onehalogen atom, or organometallic compounds having a metal-metal bond, ofsilicon, germanium, titanium, tin, zirconium, aluminum, antimony,arsenic, barium, bismuth, boron, calcium, cerium, chromium, copper,erbium, gallium, hafnium, indium, iron, lanthanum, magnesium, manganese,neodymium, niobium, praseodymium, samarium, strontium, tantalum,tellurium, tungsten, vanadium, yttrium, and zinc, and specificallypreferably of silicon, germanium, titanium, tin, zirconium and aluminum,among them.

Further, an alcohol component to constitute alkoxides includes straightchain or branched chain alcohols generally having a carbon number ofapproximately 1-12, and alkoxide compounds either may be comprised ofall alcohols or provided with a ligand such as an unsubstituted orsubstituted alkyl group, an unsubstituted or substituted aryl group, andacetylacetone, provided there is at least one alkoxide in the compound.Further, as halogens to constitute organometallic compounds having abond between a metal and at least one halogen atom, at least one type ofa halogen atom selected from chlorine, bromine and iodine can beutilized without limitation, and these organometallic compounds may alsobe those provided with a ligand such as a bond between a metal and anunsubstituted or substituted alkyl group, a bond between a metal and anunsubstituted or substituted aryl group, and acetylacetone, provided thecompound has at least one metal-halogen bond.

The mixing ratio of above-described titanium oxide, calcium carbonate,magnesium oxide and aluminum oxide which have been subjected to asurface treatment by a hydrophobicity providing agent is preferablyapproximately 1-20 weight %, more preferably approximately 1-10 weight %and furthermore preferably approximately 5-10 eight %.

Further, a mean particle diameter of the aforesaid colorant ispreferably in a range of 0.1-1.0 μm with respect to a covering power andwhiteness.

A matrix polymer utilized in a polymer solid electrolyte, whichconstitutes polymer solid electrolyte layer 14 containing a metal ion,includes polyethylene oxide, polypropylene oxide, polyethylene imine andpolyethylene sulfide, and resin provided with them as a main chainstructure or a branched chain structure. Further, resin such aspolymethyl methacrylate, polyvinylidene fluoride, polyvinylidenechloride, polycarbonate and polyacrylonitrile can be also preferablyutilized as a matrix polymer applied for a polymer solid electrolyte ofthis invention.

The layer thickness of polymer solid electrolyte layer 14 is preferably20-200 μm, more preferably 50-150 μm and furthermore preferably 70-150μm. The thinner is the layer, the smaller is the resistance betweenelectrodes, resulting in decrease of coloration-discoloration time anddepression of electricity consumption, which is preferable. However,when it is less than 20 μm, it is not preferable that mechanicalstrength is lowered to generate such as pinholes and cracks. Further,when it is too thin, the mixing amount of white particles becomes smallresulting in insufficient covering power and whiteness (opticaldensity).

Further, when the aforesaid polymer solid electrolyte layer 14 isformed, a solvent, such as water, ethyl alcohol, isopropyl alcohol,propylene carbonate, dimethyl carbonate, ethylene carbonate,γ-butyrolactone, acetonitrile, sulforane, dimethoxyethane,dimethylformamide, dimethylsulfoxide, dimethylacetoamide and N-metylpyrrolidone may be appropriately added to prepare the polymer solidelectrolyte layer forming composition.

Further, in the case of forming polymer solid electrolyte layer 14, anionic fluid represented by Q⁺A⁻ may be added instead of theabove-described solvent for the purpose of efficiently performing ionicconduction or decreasing the amount of the combustible liquid, and suchan ionic fluid is a salt which presents as a liquid at 20-100° C.,preferably at 20-80° C., more preferably at 20-60° C., furthermorepreferably at 20-40° C. and specifically preferably at 20° C. Theviscosity (at 25° C.) is not specifically limited provided being a meltat ordinary temperature, however, preferably 1-200 mPa.s. Further, acationic component represented by Q⁺ is preferably an onium cation andmore preferably an ammonium cation, an imidazolium cation, a pyridiniumcation and a sulfonium cation.

Specific examples of such an ionic fluid are described in WO95/18456,JP-A Nos. 8-245828, 8-259543, 10-92467, 10-265673, 2002-99001,2002-11,0225, 2001-243995, European Patent No. 718288, Electrochemistry,Vol. 65, No. 11 923 (1997), J. Electrochem. Soc., Vol. 143, No. 10, 3099(1996), and Inorg. Chem. 35, 1168-1178 (1996), and these can be utilizedby appropriate selection.

Further, in this embodiment, a bluing agent or a fluorescent whiteningagent may be added to improve visual whiteness by such as fluorescenceor bluing, and these can be utilized by appropriate selection fromcommonly known compounds.

A bluing agent includes organic dyes and pigments or inorganic pigmentswhich can provide blue coloring, specifically, such as ultramarine,cobalt blue, cobalt phosphate, quinacridone type pigment and mixturesthereof.

Fluorescent whitening agents described above include, for example, astilbene type, a pyrazoline type, an oxazole type, a coumarin type, animidazole type, a distyryl-biphenyl type, a thiazole type, a triazoletype, an oxazole type, a thiadiazole type, a naphthalimide type, abenzoimidazole type, a benzooxazole type, a benzothiazole type, aacenaphthene type and a diaminostilbene type.

As specific examples of a bluing agent or a fluorescent whitening agentdescribed above, those described in such as JP-A Nos. 6-322697,7-181626, 8-118824, 8-175033, 10-44628, 11-60923, 11-295852, 11-286174,2001-209149, 2001-232737 and 2002-284978, and Japanese Translated PCTPatent Publication Nos. 11-513736 and 2001-518919 can be utilized byappropriate selection.

Herein, the content of a bluing agent or a fluorescent whitening agentis preferably 10-100,000 ppm and. specifically preferably 50-10,000 ppm.When the content of a bluing agent or a fluorescent whitening agent isless than 10 ppm, there is a tendency of the emission quantity offluorescence become small to decrease the bluing component of thereflective light resulting in insufficient whiteness due to yellowing ofthe film, which is not preferable. While the content of a bluing agentor a fluorescent whitening agent is over 100,000 ppm, color change, whena bluing agent or a fluorescent whitening agent are modified, becomessignificant in the case of utilizing the display apparatus underconditions of ultraviolet irradiation or of high temperature and highhumidity, resulting in possible deterioration of weather-proofing as adisplay apparatus.

In this invention, common electrode 15 is formed as the second electrodeon the side facing to the first transparent electrode. This commonelectrode 15 is comprised of any material provided it is anelectrochemically stable metal, and preferable are such as platinum,chromium, aluminum, cobalt and palladium, a layer of which can beprepared as a metal layer on a support by a commonly known method.Further, a coated layer on a support of conductive paint, which containsconductive particles such as carbon and conductive metal particles canbe utilized as a common electrode provided a sufficient conductivity canbe obtained, and further carbon can be utilized as a common electrodeprovided a metal utilized for a main reaction can be sufficientlysupplied in advance or on demand. A method to make carbon be supportedon an electrode includes a method in which carbon is made into ink byuse of resin and printed on the substrate surface. The cost of anelectrode can be decreased by utilizing carbon.

As support 16, the aforesaid support utilized to provide the firsttransparent electrode can be appropriately utilized; however, the secondelectrode is not necessarily transparent and such as a substrate and afilm, which are possible to firmly hold such as a common electrode and apolymer solid electrolyte layer, can be utilized by appropriateselection. Further, as shown in FIG. 2, sealing member 17, which holdstransparent support 11 and support 16, is arranged at the circumferenceof the apparatus so as to make the first transparent electrode side andthe second electrode face to each other. Transparent support 11 andsupport 16, including transparent pixel electrode 12, TFT 13, polymersolid electrolyte layer 14 and common electrode which are arrangedbetween them, are firmly held by this sealing member 17. Hereinanti-reflecting layer 18 is arranged at the outermost layer to beobserved of support 16, on which the first transparent electrode isprovided.

According to the above-described structure, in an apparatus of thisinvention, matrix drive is possible by use of a TFT, contrast and blackdensity can be increased by utilizing a metal ion contained in polymersolid electrolyte layer, and a display apparatus having a visuallyfurther improved reflectance can be prepared since an anti-reflectinglayer having a lower refractive index is provided on the side on which adisplay portion is observed.

Next, a manufacturing method of a display apparatus of this inventionwill be detailed based on FIGS. 3( a) -3(f), FIGS. 4( a) -4(f) and FIGS.5( a) -5(f).

Firstly, as shown in FIG. 3( a), an anti-reflecting layer 18 is formedby utilizing a commonly known method which is suitable to a compound toform anti-reflecting layer 18 and a transparent support. Such as a MgF₂layer and a AlF₂·MgF₂ layer are formed on the whole substrate by meansof evaporation or spattering method. Next, as shown in FIG. 3( b),transparent pixel electrode 12, which is comprised of an ITO layer, andTFT 13 are formed for each pixel on the surface of support 11 oppositeto anti-reflecting layer 18. TFT 13 is formed by utilizing commonlyknown semiconductor manufacturing techniques, and an ITO layer is formedby a method such as evaporation and spattering. These transparent pixelelectrode 12 and TFT 13 are formed for each pixel, and said each pixelis arranged in a matrix form on transparent support 11.

After transparent pixel electrode 12 and TFT 13 are formed ontransparent support 11 in this manner, as shown in FIG. 3( c), polymersolid electrolyte layer 14 is formed on the surface of transparentsupport 11, on which transparent pixel electrode 12 and TFT 13 have beenformed. In this process to form polymer solid electrolyte layer 14,first, in advance to form polymer solid electrolyte layer 14, theaforesaid resin to form a matrix polymer, a support electrolyte, a metalion generating agent which can produce a metal ion and appropriately asolvent to dissolve these materials are mixed, and white particles as acolorant are further dispersed therein, resulting in preparation of apolymer solid electrolyte layer forming composition. Next, polymer solidelectrolyte layer 14 is formed by coating this polymer solid electrolytelayer forming composition on a transparent support.

Separately, as shown in FIG. 3( d), a support provided with a commonelectrode is prepared by forming common electrode 15 comprising apalladium layer having a predetermined thickness on support 16comprising such as polyethylene terephthalate, and the common electrode15 side of this support provided with a common electrode is pressed ontopolymer solid electrolyte layer 14 to be pasted up together as shown inFIG. 3( e). After having been pasted up, the laminate is dried underreduced pressure resulting in formation of polymer solid electrolytelayer 14 between support 16 and transparent support 11. Successively,sealing member 17 as shown in FIG. 3( f) is attached to the edge portionof the pasted-up laminate to complete a display apparatus in whichanti-reflecting layer 18 is provided on the display side.

Further, FIGS. 5( a)-5(f) illustrate a manufacturing method of a displayapparatus of the embodiment different from the manufacturing methodshown in FIGS. 3( a)-3(f) and FIGS. 4( a)-4(f), and firstly, as shown inFIG. 5( a), transparent pixel electrode 12 comprising an ITO layer andTFT (Thin Layer Transistor) 13 are formed for each pixel on transparentsupport 11 such as a glass substrate. TFT 13 is formed by utilizingcommonly known semiconductor manufacturing techniques, and an ITO layeris formed by a method such as evaporation and spattering. Thesetransparent pixel electrode 12 and TFT 13 are formed for each pixel, andsaid each pixel is arranged in a matrix form on transparent support 11.

After transparent pixel electrode 12 and TFT 13 are formed ontransparent support 11 in this manner, as shown in FIG. 5( b), polymersolid electrolyte layer 14 is formed on the surface of transparentsupport 11, on which transparent pixel electrode 12 and TFT 13 have beenformed. In this process to form polymer solid electrolyte layer 14,first, in advance to form polymer solid electrolyte layer 14, theaforesaid resin to form a matrix polymer, a support electrolyte, a metalion generating agent which can produce a metal ion and appropriately asolvent to dissolve these materials are mixed, and white particles as acolorant are further dispersed therein, resulting in preparation of apolymer solid electrolyte layer forming composition. Next, polymer solidelectrolyte layer 14 is formed by coating this polymer solid electrolytelayer forming composition on a transparent support.

Separately, as shown in FIG. 5( c), a support provided with a commonelectrode is prepared by forming common electrode 15 comprising apalladium layer having a predetermined thickness on support 16comprising such as polyethylene terephthalate, and the common electrode15 side of the support provided with a common electrode is pressed ontopolymer solid electrolyte layer 14 to be pasted up together as shown inFIG. 5( d). After having been pasted up, the laminate is dried underreduced pressure resulting in formation of polymer solid electrolytelayer 14 between support 16 and transparent support 11. Successively,sealing member 17 as shown in FIG. 5( e) is attached to the edge portionof the pasted-up laminate, and finally, as shown in FIG. 5( f),anti-reflecting layer 18, such as a MgF₂ layer and a LlF₃·MgF₂ layerbeing formed on the whole substrate by means of evaporation orspattering method, is formed according to a commonly known method on theimage displaying surface of support 11, to complete a display apparatusin which anti-reflecting layer 18 is provided on the display side.

FIG. 6 is a block diagram of a display apparatus. Transparent pixelelectrode 12 for each pixel and corresponding TFT 13 are arranged in amatrix form, and the opposing electrode side of the capacity makes acommon electrode. To the gate electrode of TFT 13 is connected gate line(scanning line wiring) 140, while the one end of the source and drain ofTFT 13 each are connected to data line (data line wiring) 150. The otherend of the source and drain of TFT 13 each are connected to transparentpixel electrode 12. Gate line 140 is connected to gate line drivecircuit 120, and data line 150 is connected to data line drive circuit100 and 110. Gate line drive circuit 120, data line drive circuit 100and 110 are connected to signal control section 130.

EXAMPLES

In the following, the present invention will be explained according toexamples, however, the present invention is not limited to theseembodiments.

Example 1

(Manufacture of Display Apparatus, Preparation and Coating of PolymerSolid Electrolyte)

MgF₂ was evaporated from an evaporation source comprising MgF₂ onto aglass substrate of 1.5 mm thick and 10 ×10 cm in size to form anevaporated layer of MgF₂ having a thickness of 1600 Å, resulting information of an anti-reflecting layer. Next, an ITO layer and a TFT,which were arranged in a plane at a 150 μm pitch, were prepared on thesurface opposite to the anti-reflecting layer of the glass substrate.Successively, 1 weight part of polyvinylidene fluoride having amolecular weight of approximately 350,000, 10 weight parts of a 1/1mixed solution of water and isopropylalcohol, 1.7 weight parts oflithium bromide and 1.7 weight parts of bismuth chloride were mixed andheated at 120° C. to prepare a homogeneous solution. Titanium dioxide,having a mean particle diameter of 0.5 μm, of 0.2 weight parts was addedthereto and the resulting solution was uniformly dispersed by use of ahomogenizer. Immediately after coating this solution on theabove-described glass substrate by a doctor blade at a thickness of 60μm, a common electrode explained below as the second electrode waspasted up thereon, and the resulting laminate was dried under reducedpressure at 110° C. and 0.05 MPa for 1 hour resulting in formation of apolymer solid electrolyte layer between two electrodes. Next, the edgesurface of the laminate was sealed by an adhesive to prepare a displayapparatus.

(The Second Electrode (Counter Electrode, Common Electrode))

A palladium layer having a thickness of 3000 Å was formed by means ofspattering on a polyethylene terephthalate film having a 0.5 mm thickand 10 cm×10 cm in size. This was pressing adhered onto theabove-described polymer solid electrolyte layer immediately after thelayer had been coated.

(Evaluation of Drive and Display Characteristics)

Black color display and a colorless (white) display were switched by useof a commonly known active matrix drive circuit, by oxidizing a displayelectrode with a quantity of electricity of 5 μC per one pixel at thetime of coloring and reducing with the same quantity of electricity atthe time of discoloration. The reflectivity at the time of colorless(white) was 68%, and the optical density (OD) of the display portion atthe time of coloring (black) was approximately 0.8 (a reflectivity of8%). Therefore, as a contrast of reflectivity, 1/8.5 was obtained. Afterhaving been held in a colored state, the display apparatus was storedwhile opening the circuit, to show no significant change of opticaldensity of the display portion and to maintain memory ability after 1week.

(Sensual Evaluation of Identification)

When a display element prepared in above example 1 and one prepared incomparative example 1 shown below were evaluated by 50 persons, 90% ofthe persons have judged that the display apparatus provided with ananti-reflecting layer was easier to be seen.

Example 2

A display apparatus was prepared under similar conditions to example 1,except that silver perchloride was employed instead of bismuth chlorideutilized in example 1.

Successively, the sample was driven and evaluated in a similar manner toexample 1, to determine that the reflectivity at the time of colorless(white) was 70%, and the optical density (OD) of the display portion atthe time of coloring (black) was approximately 1.0 (a reflectivity of7%). Therefore, as a contrast of reflectivity, 1/10 was obtained. Afterhaving been held in a colored state, the display apparatus was storedwhile opening the circuit, to show no significant change of opticaldensity of the display portion and to maintain memory ability after 1week. Further, when the display apparatus prepared in example 2 and oneprepared in comparative example 2 shown below were evaluated by 50persons, 94% of the persons have judged that the display apparatusprovided with an anti-reflecting layer was easier to be seen.

Example 3

(Manufacture of Display Apparatus, Preparation and Coating of PolymerSolid Electrolyte)

An ITO layer and a TFT, which were arranged in a plane at a 150 μmpitch, were formed onto a glass substrate of 1.5 mm thick and 10×10 cmin size according to a commonly known method. Next, spattering wasperformed onto the surface opposite to the surface, on which an ITOlayer and a TFT were provided, of the glass substrate by utilizing analloy comprising metal aluminum, in which metal magnesium was mixed at aatom composition ratio of 30%, as a metal target, and employing an Argas as a spatter gas and a 5% diluted F₂ gas as a reaction gas,resulting in formation of an AlF₃·MgF₂ anti-reflecting layer having athickness of 300 nm. Successively, 1 weight part of polyvinylidenefluoride having a molecular weight of approximately 350,000, 10 weightparts of a 1/1 mixed solution of water and isopropyl alcohol, 1.7 weightparts of lithium bromide and 1.7 weight parts of bismuth chloride weremixed and heated at 120° C. to prepare a homogeneous solution. Titaniumdioxide, having a mean particle diameter of 0.5 μm, of 0.2 weight partswas added thereto and the resulting solution was uniformly dispersed byuse of a homogenizer. Immediately after coating this solution on theabove-described glass substrate by a doctor blade at a thickness of 60μm, a common electrode explained in example 1 as the second electrodewas pasted up thereon, and the resulting laminate was dried underreduced pressure at 110° C. and 0.05 MPa for 1 hour, resulting information of a polymer solid electrolyte layer between two electrodes.Next, the edge surface of the laminate was sealed by an adhesive toprepare a display apparatus.

Successively, the sample was driven and evaluated in a similar manner toexample 1, to determine that the reflectivity when being colorless(white) was 70%, and the optical density (OD) of the display portionwhen being at the time of colored (black) was approximately 1.0 (areflectivity of 6%). Therefore, as a contrast of reflectivity, 1/11.7was obtained. After having been held in a colored state, the displayapparatus was stored while opening the circuit, to show no significantchange of optical density of the display portion and to maintain memoryability after 1 week. Further, when the display apparatus prepared inexample 3 and one prepared in comparative example 2 shown below wereevaluated by 50 persons, 94% of the persons have judged that the displayapparatus provided with an anti-reflecting layer was easier to be seen.

Example 4

(Manufacture of Display Apparatus, Preparation and Coating of PolymerSolid Electrolyte)

An ITO layer and a TFT, which were arranged in a plane at a 150 μmpitch, were formed onto a glass substrate of 1.5 mm thick and 10×10 cmin size according to a commonly known method. Successively, 1 weightpart of polyvinylidene fluoride having a molecular weight ofapproximately 350,000, 10 weight parts of a 1/1 mixed solution of waterand isopropyl alcohol, 1.7 weight parts of lithium bromide and 1.7weight parts of bismuth chloride were mixed and heated at 120° C. toprepare a homogeneous solution. Titanium dioxide, having a mean particlediameter of 0.5 μm, of 0.2 weight parts was added thereto and theresulting solution was uniformly dispersed by use of a homogenizer.Immediately after coating this solution on the above-described glasssubstrate by a doctor blade at a thickness of 60 μm, a common electrodeexplained in example 1 as the second electrode was pasted up thereon,and the resulting laminate was dried under reduced pressure at 110° C.and 0.05 MPa for 1 hour, resulting in formation of a polymer solidelectrolyte layer between two electrodes. Then, the edge surface of thelaminate was sealed by an adhesive. Next, MgF₂ was evaporated from anevaporation source comprising MgF₂ onto a glass substrate of 1.5 mmthick and 10×10 cm in size to form an evaporated layer of MgF₂ having athickness of 1600 Å, resulting in formation of an anti-reflecting layerand preparation of a display apparatus.

Successively, the sample was driven and evaluated in a similar manner toexample 1, to determine that the reflectivity when being colorless(white) was 70%, and the optical density (OD) of the display portionwhen being colored (black) was approximately 1.0 (a reflectivity of 7%).Therefore, as a contrast of reflectivity, 1/10 was obtained. Afterhaving been held in a colored state, the display apparatus was storedwhile opening the circuit, to show no significant change of opticaldensity of the display portion and to maintain memory ability after 1week. Further, when the display apparatus prepared in example 4 and oneprepared in comparative example 2 shown below were evaluated by 50persons, 94% of the persons have judged that the display apparatusprovided with an anti-reflecting layer was easier to be seen.

Example 5

(Manufacture of Display Apparatus, Preparation and Coating of PolymerSolid Electrolyte)

MgF₂ was evaporated from an evaporation source comprising MgF₂ onto aglass substrate of 1.5 mm thick and 10 ×10 cm in size to form anevaporated layer of MgF₂ having a thickness of 1600 Å, resulting information of an anti-reflecting layer. Next, an ITO layer and a TFT,which were arranged in a plane at a 150 μm pitch, were prepared on thesurface opposite to anti-reflecting layer of the glass substrate.Successively, 1 weight part of polyvinylidene fluoride having amolecular weight of approximately 350,000, 10 weight parts of a 1/1mixed solution of water and isopropyl alcohol, 1.7 weight parts oflithium bromide and 1.7 weight parts of bismuth chloride were mixed andheated at 120° C. to prepare a homogeneous solution. Titanium dioxide,having a mean particle diameter of 0.5 μm, the surface of which had beensubjected to a surface treatment by dimethyldichlorosilane, of 0.2weight parts was added thereto and the resulting solution was uniformlydispersed by use of a homogenizer. Immediately after coating thissolution on the above-described glass substrate by a doctor blade at athickness of 60 μm, a common electrode explained in example 1 as thesecond electrode was pasted up thereon, and the resulting laminate wasdried under reduced pressure at 110° C. and 0.05 MPa for 1 hourresulting in formation of polymer solid electrolyte layer between twoelectrodes. Next, the edge surface of the laminate was sealed by anadhesive to prepare a display apparatus.

Successively, the sample was driven and evaluated in a similar manner toexample 1, to determine that the reflectivity when being colorless(white) was 70%, and the optical density (OD) of the display portionwhen being colored (black) was approximately 0.8 (a reflectivity of 8%).Therefore, as a contrast of reflectivity, 1/8.5 was obtained. Afterhaving been held in a colored state, the display apparatus was storedwhile opening the circuit, to show no significant change of opticaldensity of the display portion and to maintain memory ability after 1week. Further, when the display apparatus prepared in example 5 and oneprepared in comparative example 3 shown below were evaluated by 50persons, 90% of the persons have judged that the display apparatusprovided with an anti-reflecting layer was easier to be seen. Further,the reflectivity of the colorless portion (white portion) was 70% after1.5 months, which was not significantly changed.

Example 6

(Manufacture of Display Apparatus, Preparation and Coating of PolymerSolid Electrolyte)

An ITO layer and a TFT, which were arranged in a plane at a 150 μmpitch, were formed onto a glass substrate of 1.5 mm thick and 10×10 cmin size according to a commonly known method. Next, spattering wasperformed onto the surface opposite to the surface, on which an ITOlayer and a TFT were provided, of the glass substrate by utilizing analloy comprising metal aluminum, in which metal magnesium was mixed at aatom composition ratio of 30%, as a metal target, and employing an Argas as a spatter gas and a 5% diluted F₂ gas as a reaction gas,resulting in formation of an AlF₃·MgF₂ anti-reflecting layer having athickness of 300 nm.

Successively, 1 weight part of polyvinylidene fluoride having amolecular weight of approximately 350,000, 10 weight parts of a 1/1mixed solution of water and isopropyl alcohol, 1.7 weight parts oflithium bromide and 1.7 weight parts of bismuth chloride were mixed andheated at 120° C. to prepare a homogeneous solution. Titanium dioxide,having a mean particle diameter of 0.5 μm and having been subjected to asurface treatment by γ-glycidoxypropyl trimethoxysilane, of 0.2 weightparts was added thereto and the resulting solution was uniformlydispersed by use of a homogenizer. Immediately after coating thissolution on the above-described glass substrate by a doctor blade at athickness of 60 μm, a common electrode explained in example 1 as thesecond electrode was pasted up thereon, and the resulting laminate wasdried under reduced pressure at 110° C. and 0.05 MPa for 1 hour,resulting in formation of a polymer solid electrolyte layer between twoelectrodes. Next, the edge surface of the laminate was sealed by anadhesive to prepare a display apparatus.

Successively, the sample was driven and evaluated in a similar manner toexample 1, to determine that the reflectivity when being colorless(white) was 72%, and the optical density (OD) of the display portionwhen being at the time of colored (black) was approximately 1.0 (areflectivity of 7%). Therefore, as a contrast of reflectivity, 1/10 wasobtained. After having been held in a colored state, the displayapparatus was stored while opening the circuit, to show no significantchange of optical density of the display portion and to maintain memoryability after 1 week. Further, when the display apparatus prepared inexample 3 and one prepared in comparative example 2 shown below wereevaluated by 50 persons, 94% of the persons have judged that the displayapparatus provided with an anti-reflecting layer was easier to be seen.Further, the reflectivity of the colorless portion (white portion) was72% even after 1.5 months, which was not significantly changed.

Example 7

A display apparatus was prepared in a similar manner to example 1,except that titanium oxide having a mean particle diameter of 0.5 μm andhaving been subjected to a surface treatment by methyl trimethoxysilanein stead of titanium dioxide, having a mean particle diameter of 0.5 μmand having been subjected to a surface treatment by γ-glycidoxypropyltrimethoxysilane, which was utilized in example 6. Successively, thesample was driven and evaluated in a similar manner to example 1, todetermine that the reflectivity when being colorless (white) was 72%,and the optical density (OD) of the display portion when being colored(black) was approximately 1.0 (a reflectivity of 7%). Therefore thecontrast of reflectivity was 1/7. After having been held in a coloredstate, the display apparatus was stored while opening the circuit, toshow no significant change of optical density of the display portion andto maintain memory ability after 1 week. Further, when the displayapparatus prepared in example 7 and one prepared in comparative example4 shown below were evaluated by 50 persons, 94% of the persons havejudged that the display apparatus provided with an anti-reflecting layerwas easier to be seen. Further, the reflectivity of the colorlessportion (white portion) was 72% even after 1.5 months, which was notsignificantly changed.

Comparative Example 1

A display apparatus was prepared under conditions similar to example 1,except that anti-reflecting layer, which was formed on a glass substratein example 1, was not provided. Successively, the sample was driven andevaluated in a similar manner to example 1, to determine that thereflectivity when being colorless (white) was 70%, and the opticaldensity (OD) of the display portion when being colored (black) wasapproximately 0.8 (a reflectivity of 13%). Therefore the contrast ofreflectivity was ⅕. After having been held in a colored state, thedisplay apparatus was stored while opening the circuit, to show nosignificant change of optical density of the display portion and tomaintain memory ability after 1 week.

Comparative Example 2

A display apparatus was prepared under conditions similar to example 4,except that anti-reflecting layer, which was formed on a glass substratein example 4, was not provided. Successively, the sample was driven andevaluated in a similar manner to example 1, to determine that thereflectivity when being colorless (white) was 72%, and the opticaldensity (OD) of the display portion when being colored (black) wasapproximately 1.0 (a reflectivity of 10%). Therefore the contrast ofreflectivity was 1/7. After having been held in a colored state, thedisplay apparatus was stored while opening the circuit, to show nosignificant change of optical density of the display portion and tomaintain memory ability after 1 week.

Comparative Example 3

A display apparatus was prepared under conditions similar to example 5,except that anti-reflecting layer, which was formed on a glass substratein example 5, was not provided and titanium dioxide without a surfacetreatment and having a mean particle diameter of 0.5 μm was utilizedinstead of titanium dioxide having been subjected to a surface treatmentby dimethyldichlorosilane and having a mean particle diameter of 0.5 μm.Successively, the sample was driven and evaluated in a similar manner toexample 1, to determine that the reflectivity when being colorless(white) was 70%, and the optical density (OD) of the display portionwhen being colored (black) was approximately 0.8 (a reflectivity of13%). Therefore the contrast of reflectivity was ⅕. After having beenheld in a colored state, the display apparatus was stored while openingthe circuit, to show no significant change of optical density of thedisplay portion and to maintain memory ability after 1 week. Further,the reflectivity of the colorless portion (the white portion) after 1.5months was 66%, which was somewhat deteriorated.

Comparative Example 4

A display apparatus was prepared under conditions similar to example 6,except that anti-reflecting layer, which was formed on a glass substratein example 6, was not provided and titanium dioxide without a surfacetreatment and having a mean particle diameter of 0.5 μm was utilizedinstead of titanium dioxide having been subjected to a surface treatmentby γ-glycidoxypropyl trimethoxysilane and having a mean particlediameter of 0.5 μm. Successively, the sample was driven and evaluated ina similar manner to example 1, to determine that the reflectivity whenbeing colorless (white) was 72%, and the optical density (OD) of thedisplay portion when being colored (black) was approximately 1.0 (areflectivity of 10%). Therefore the contrast of reflectivity was 1/7.After having been held in a colored state, the display apparatus wasstored while opening the circuit, to show no significant change ofoptical density of the display portion and to maintain memory abilityafter 1 week. Further, the reflectivity of the colorless portion (thewhite portion) after 1.5 months was 67%, which was somewhatdeteriorated.

The present invention can provide a display element, a display apparatusand a manufacturing method thereof, utilizing a material, which has anincreased whiteness of a background as a visual characteristic andchanges color by an electrochemical redox reaction, as a displaymaterial.

1. A display element comprising: (a) a first electrode which istransparent and is controlled by a driver element; (b) a secondelectrode; and (c) a solid polymer electrolyte layer containing acolorant and metal ions, wherein: said metal ions are chosen from silverions, bismuth ions, and mixtures thereof; said solid polymer electrolytelayer is provided between the first electrode and the second electrode;said colorant is selected from the group consisting of a powder oftitanium oxide, calcium carbonate, magnesium oxide and aluminum oxide,wherein a surface of the powder is treated with a hydrophobicity-givingagent; and the first electrode has an anti-reflecting layer on a sideopposite to the solid polymer electrolyte layer.
 2. The display elementof claim 1, wherein the first electrode is provided on a transparentsubstrate.
 3. The display element of claim 2, wherein theanti-reflecting layer has a smaller reflection index than thetransparent substrate.
 4. The display element of claim 3, wherein theanti-reflecting layer contains a fluorinated compound as a maincomponent.
 5. The display element of claim 1, wherein an averagediameter of the colorant is from 0.1 to 1.0 μm.
 6. The display elementof claim 1, wherein the hydrophobicity-giving agent is a metal alkoxide,an organometallic compound containing a metal-to-halogen bond in themolecule or an organometallic compound containing a metal-to-metal bondin the molecule.
 7. The display element of claim 1, wherein the firstelectrode which is transparent comprises SnO₂, In₂O₃ or mixturesthereof.
 8. The display element of claim 1, wherein the second electrodeis a metallic thin film.
 9. The display element of claim 1, wherein thesolid polymer electrolyte is selected from the group consisting ofpolyethyleneoxide, polypropyleneoxide, polyethyleneimine,polyethyelenesulfide, polymethylmethacrylate, polyfluorovinylidene,polychlorovinylidene, polycarbonate, polyacryonitrile and mixturesthereof, or a plurality of layers thereof; provided that the solidpolymer electrolyte further contains a metal sait or an alkylammoniumsalt.
 10. A display apparatus comprising a plurality of display elementsaccording to claim 1, wherein said display apparatus forms a displaypanel.
 11. The display element of claim 1, wherein the solid polymerelectrolyte layer further comprises a bluing agent or a fluorescentwhitening agent.
 12. A method of producing a display apparatuscomprising the steps in the order named: (a) forming an anti-reflectinglayer on a transparent substrate; (b) forming a transparent electrodeand a driver element on the transparent substrate on a side opposite tothe anti-reflecting layer; (c) forming a solid polymer electrolyte layercontaining a colorant and metal ions on the transparent substrate,wherein: said metal ions are chosen from silver ions, bismuth ions, andcombinations thereof; said colorant is selected from the groupconsisting of a powder of titanium oxide, calcium carbonate, magnesiumoxide, and aluminum oxide, wherein a surface of the powder is treatedwith a hydrophobicity-giving agent; and (d) forming a common electrodeat an opposed position to the transparent electrode.
 13. A method ofproducing a display apparatus comprising the steps in the order named:(a) forming a transparent electrode and a driver element on atransparent substrate; (b) forming a solid polymer electrolyte layercontaining a colorant and metal ions on the transparent substrate,wherein: said metal ions beingare chosen from silver ions, bismuth ions,and combinations thereof; said colorant is selected from the groupconsisting of a powder of titanium oxide, calcium carbonate, magnesiumoxide, and aluminum oxide, wherein a surface of the powder is treatedwith a hydrophobicity-giving agent; (c) forming a common electrode at anopposed position to the transparent electrode; and (d) forming ananti-reflecting layer on the transparent substrate at a side opposite tothe transparent electrode and the driver element.
 14. A method ofproducing a display apparatus comprising the steps in the order named:(a) forming a transparent electrode and a driver element on atransparent substrate; (b) forming an anti-reflecting layer on thetransparent substrate at a side opposite to the transparent electrodeand the driver element; (c) forming a solid polymer electrolyte layercontaining a colorant and metal ions on the transparent substrate on aside which is formed the transparent electrode and the driver element,wherein: said metal ions being chosen from silver ions, bismuth ions,and combinations thereof; said colorant is selected from the groupconsisting of a powder of titanium oxide, calcium carbonate, magnesiumoxide, and aluminum oxide, wherein a surface of the powder is treatedwith a hydrophobicity-giving agent; and (d) forming a common electrodeat an opposed position to the transparent electrode.